Submitted to: Meeting Proceedings
Publication Type: Proceedings
Publication Acceptance Date: 7/11/2013
Publication Date: 9/10/2013
Citation: Harvey, R.B., Genovese, K.J., He, L.H., Nisbet, D.J. 2013. Innate immune response induced in gnotobiotic piglets by a mixed culture of commensal bacteria. Proceedings of the 2013 Safe Pork International Conference on the Epidemiology and Control of Foodborne Pathogens and Antimicrobial Resistance in Pigs and Pork. pp. 2-3.
Interpretive Summary: Our laboratory has developed a mixed bacterial culture from pigs (RPCF) that, when given to newborn piglets, protects them from disease caused by Salmonella and E. coli bacteria. The mechanism of protection remains elusive. We speculated that the reason for protection might be related to improved innate immune function. We dosed gnotobiotic (bacterially sterile) piglets with RPCF and observed increased immune measurements in the treated versus untreated piglets. This is important to swine producers because the use of RPCF could decrease disease and increase productivity in swine which will translate into economic benefits.
Technical Abstract: Our laboratory has developed a recombined porcine-derived mixed bacterial culture (RPCF) isolated from the ceca of a healthy, pathogen-free pig and have maintained it at steady state in a continuous-flow chemostat. The culture has been shown to protect neonatal and weaned pigs from infection and disease caused by Salmonella and E. coli. However, the mechanism of action of the protection from pathogens observed with the RPCF culture remains unclear. In the present study, 40 piglets were delivered by caesarian section and reared under gnotobiotic conditions. Piglets were either given RPCF within 1 hr after birth or were given sterile media. At times 0, 8, 24, 48, and 72 hr post-birth, piglets were euthanized and samples of spleen taken. Splenic cells from individual piglets were isolated and cultured with or without concanavalin A (conA). Splenic cells from RPCF-treated piglets had increased levels of IL-1ß, IFN-gamma, IL-18, and IL-10 at 8 hr after birth compared to control piglets as measured by porcine cytokine ELISA. The increased levels of cytokines produced by RPCF-treated piglet splenocytes then declined over time, returning to levels observed in control pigs or, in some instances, below control levels. These results suggest that RPCF may act as a modulator for certain aspects of innate immune development.